Current linear aeroelastic analysis approaches are not suited for capturing the emerging concerns in bridge aerodynamics introduced by aerodynamic nonlinearities and turbulence effects. These issues may become critical for bridges with increasing spans and/or with aerodynamic characteristics sensitive to the effective angle of incidence. This paper presents a nonlinear aerodynamic force model a...

System identification is evaluated as an efficient and accurate technique for modeling unsteady aerodynamic forces for use in time-domain aeroelastic analysis. In the system identification methodology, the constant coefficients of a linear system model are fit to the computed response time histories from a 3-D, unsteady CFD solver. The resulting model of the unsteady CFD solution is independent...

A novel method to estimate unsteady aerodynamic force coefficients from pointwise velocity measurements is presented. The methodology is based on a resolvent-based reducedorder model which requires the mean flow to obtain physical flow structures and pointwise measurement to calibrate their amplitudes. A computationally-affordable time-stepping methodology to obtain resolvent modes in non-trivi...

The paper presents work on testing of inflatable wings for unmanned aerial vehicles (UAVs). Inflatable wing history and recent research is discussed. Design and construction of inflatable wings is then covered, along with ground and flight testing. Discussions include predictions and correlations of the forces required to warp (twist) the wings to a particular shape and the aerodynamic forces g...

This paper describes recent development on the design of the flight control system for a Micromechanical Flying Insect (&PI), a 10-25mm (wingtipto-wingtip) device capable of sustained autonomous flight. High level attitude control is considered. Based on our previous work [l], in which the complex time-varying component of aerodynamic forces are treated as extemal disturbances, a nominal state-...

We present a self-consistent two-dimensional fluid model of the temporal and spatial development of the One Atmosphere Uniform Glow Discharge Plasma (OAUGDP). Continuity equations for electrically charged species N+2 , N + 4 , O + 2 , O − 2 and electrons are solved coupled to the Poisson equation, subject to appropriate boundary conditions. It was used an algorithm proposed by Patankar. The tra...

The first force map has been generated for a 2 DOF wing designed for the MFI project. For the wing beating at a resonance frequency of 139 Hz, the average 3-D forces were found as a function of sinusoidal voltage amplitude and actuator phase difference. An image sequence of the wing trajectory allowed comparison to simulated forces using a quasi-steady state aerodynamic approximation. Finally, ...

This paper presents an integrated flight dynamic modeling method for flexible aircraft that captures coupled physics effects due to inertial forces, aeroelasticity, and propulsive forces that are normally present in flight. The present approach formulates the coupled flight dynamics using a structural dynamic modeling method that describes the elasticity of a flexible, twisted, swept wing using...

The goal of this work is to develop low order dynamical systems models for the unsteady aerodynamic forces on small wings and to better understand the physical characteristics of unsteady laminar separation. Reduced order models for a fixed, high angle of attack flat plate are obtained through Galerkin projection of the governing Navier-Stokes equations onto POD modes. Projected models are comp...

We studied the effects of wing deformation on the aerodynamic forces of wings of hovering hoverflies by solving the Navier-Stokes equations on a dynamically deforming grid, employing the recently measured wing deformation data of hoverflies in free-flight. Three hoverflies were considered. By taking out the camber deformation and the spanwise twist deformation one by one and by comparing the re...